Field of the Disclosure
The present application relates to an organic light emitting diode display device and a method of manufacturing the same.
Description of the Related Art
Recently, flat panel display devices with reduced weight and volume corresponding to disadvantages of cathode ray tube (CRT) are being developed. The flat panel display devices include liquid crystal display (LCD) devices, field emission display (FED) devices, plasma display panels (PDPs), organic light emitting diode display (OLED) devices and so on.
The OLED device is a self-luminous device which uses a thin light emission layer between electrodes. As such, the OLED device can become thinner than paper. Such an OLED device emits light through a substrate and displays images. To this end, the OLED device includes an encapsulated substrate configured with a plurality of pixel regions, a cell driver array and an organic light emission array. The plurality of pixel region each includes three color (i.e., red, green and blue) sub-pixels. Also, the plurality of pixel regions is arranged in a matrix shape.
In order to realize a variety of colors, the OLED device employs organic light emission layers emitting red, green and blue light. Each of the organic light emission layers is interposed between two electrodes and forms an organic light emitting diode (OLED).
Also, the OLED device includes a plurality of data lines used to transfer video signals, a plurality of gate lines used to transfer driving signals, and a plurality of power lines used to transfer power voltages to the organic light emitting diodes. The pluralities of data lines, gate lines and power lines cross one another and define the plurality of pixel regions. Moreover, the OLED device includes a switching thin film transistor, a driving thin film transistor, a storage capacitor and the organic light emitting diode OLED which are arranged in each of the pixel regions.
The pixel regions within the OLED device must be narrowed due to recent demands for high definition and high speed response properties. As such, it is difficult for the pixel region to secure a sufficient aperture ratio. Also, the high speed response requires thin film transistors to be used in the OLED device. Moreover, in order to enhance picture (or image) quality, a high capacity storage capacitor capable of sufficiently storing a data signal (or a video signal) must be disposed within the pixel region.
However, in order to provide a high capacitance to the pixel region, the electrode area of the storage capacitor must be enlarged. As such, the aperture ratio of the pixel region is reduced contrary to this. Therefore, it is necessary to develop a technology which realizes a large capacity storage capacitor with securing a sufficient aperture ratio of the pixel region.